Eye test determines severity of MS

January 25, 2014

Scientists have developed a simple eye test to monitor and track the severity of multiple sclerosis (MS) in patients over time.

Building on the finding that eye pupil responses in MS patients are slower than those without the condition, Australian National University researchers have developed a diagnostic test using instruments that precisely measure the speed with which pupils respond to stimuli.

The researchers said that the eye test was a simple and quick way of tracking the severity of MS over time, with the slower the pupil response was, the more advanced the condition was.

MS is a neurological condition affecting the myelin sheath of nerve fibres, leading to sensory disturbances and muscle weakness. Vision, speech and walking are most often affected, and pain can occur. MS affects different people in different ways, but the condition get worse with age. In Australia there are about 12,000 suffers, and it is the most common neurological disability in adults.

Lead researcher Professor Ted Maddess, a vision scientist at the Australian national University, said although MS seems to be some sort of immune disorder, its cause is still obscure.

“There are many puzzling aspects to MS and there are many theories, but our main aim in this work was just to find a way of accurately monitoring the progression of the disease, a single measure that relates to the degree of the disability,” Professor Madess said.

The study examined 85 patients with MS and found that the pupil response in MS patients was about 25 milliseconds slower than in a control group without the condition.

For the test, researchers used a device that emits special patterns of flashing lights. Infrared cameras capture light-induced changes in the diameter of both pupils, and computer tracking measures the diameter to within a micrometre, 30 times a second.

Professor Ted Maddess said although the study is preliminary, he believes the test has good potential for individual patients because it can precisely measure the speed of their response to within a millisecond.

“So, instead of an expensive MRI to track the condition, the new method gives an accurate readout after just a few minutes. That quick and easy test might, in future, allow MS patients to be assessed on the spot, and have their medication adjusted accordingly,” Professor Ted Maddess said.

“if we can use our pupil measurements to monitor the decline, we might be in a better position to adjust medications, which often have unpleasant side-effects.”

The device the researchers used to measure pupil response is the same as has been shown to be helpful in diagnosing vision loss in glaucoma, diabetes and age-related macular degeneration. The device was developed by Professor Maddess and colleagues, and is being commercially developed.